Transmission Electron Microscopy requires very thin specimens that are transparent to a high-intensity beam of high energy electrons. To image these samples, they are placed on a small stage at the end of a long rod in ambient room conditions that is inserted into the TEM through an airlock. Both the specimen and the stage are subject to accumulating contamination before being analyzed, in particular carbon-containing contamination. The carbon contamination creates a coating on the area being struck by the electron beam that may interfere with the imaging process by creating a loss of resolution and contrast. This contamination may be removed by Plasma cleaning in a vacuum.
Plasma cleaning can be done on the specimen and stage before insertion into the TEM instrument. Such plasma cleaning processes were first described by Zaluzec in U.S. Pat. No. 5,510,624 and expanded upon by Fischione in U.S. Pat. No. 5,633,502. Plasma cleaning of the specimens and stage occurs within a vacuum chamber pumped down to a pressure level much less than atmospheric pressure. If the specimen and stage are removed from the insertion rod before plasma cleaning and then reattached to the insertion rod after plasma cleaning, there will be recontamination of the specimen and stage. U.S. Pat. No. 5,633,502 and No. 5,922,179 describe means to transfer the specimen and stage into the plasma cleaning vacuum chamber while they are still attached to the insertion rod, thus minimizing recontamination. These transfer devices are capable of handling the different types of insertion rods produced by various electron microscope manufacturers but offer only a simple pull-in/pull-out insertion method and provide no preventive measures to avoid the specimen colliding with the inside of the sleeve. These devices require a careful insertion of the rod into a cylinder. Once cleaning is finished, the rod needs to be carefully removed from the cylinder. Damage may occur to the specimen or stage during sample insertion; damage and recontamination may occur during specimen and stage removal.